Physics:Counter efficiency

Probability P(C) of detecting a particle traversing a detector like a scintillation or proportional counter C. P(C) can be measured using a redundant setup, e.g. two detectors (T₁, T₂) of the same or smaller size and a well-defined beam such that any particle seen in T₁ and T₂ must also go through C. One obtains for P(C)

where n(T₁ T₂ C) is the number of particles detected in T₁ and T₂ and C, and n(T₁ T₂) is the number of particles seen in T₁ and T₂ regardless of what happened in C (ignoring accidental coincidences). P(C) is sensitive to the operating conditions of C and to the signal processing (thresholds, electronics, dead time).

For further discussion Detection Efficiency.